Mix the salt with the water, add the flour, mix and knead until you get a smooth dough. Rest the dough for 30 minutes. Fry the ground beef in butter. Add finely chopped onion, salt and pepper to the ground beef that has absorbed its water and fry until the onions are cooked. Divide the dough into 3 equal parts. Add tahini to the melted butter to spread between the dough. Open the meringues to the size of a phyllo and spread the oiled tahini all over the dough. Fold the edges of the dough inward and form a rectangular shape. Then fold it in half again and continue the folding process until you get a 10 cm square dough. Do the same with the other meringues and keep them in the fridge for 40 minutes. Unfold and place the folded dough on a tray. Spread half of the minced meat on the dough you opened and cover it with the other dough. Cut the dough into squares and mix it with eggs, olive oil and sugar. Sprinkle sesame and black cumin seeds and bake in the oven at 180 degrees for 30 -35 minutes. Let the pastry rest for half an hour and serve.